The Greenfield suction embolectomy catheter has been available the longest and is the only PE catheter device approved by the Food and Drug Administration (12,13). However, its limitations include a very large catheter size, requiring a surgical cutdown at the venous puncture site, as well as its stiffness, with difficulty manipulating the catheter to the desired location within the pulmonary vascular tree. In addition, there is a substantial risk of re-embolization because the aspiration pressure may not be sufficient to hold the thrombus in place while removing the catheter with the thrombus trapped within the suction cap. Thrombus fragmentation without embolectomy using balloon angioplasty or a pigtail rotational catheter has also been reported (15-17). Macroembolization, however, may cause further deterioration of hemodynamics when a large centrally located thrombus breaks and embolizes into a previously non-obstructed lobar branch (17). Several mechanical or rheolytic embolectomy devices, including Angiojet (Possis, Minneapolis, MN), Amplatz "clot buster" (BARD-Microvena, White Bear Lake, MN), or Hydrolyser (Cordis, Warren, NJ), were not designed for the use in the large-sized main pulmonary arteries but were investigated in small PE cohort studies (18-23). These catheter devices have limited efficacy to treat massive PE and are plagued by complications that include mechanical hemolysis, and macro- or microembolization (23). Mechanical hemolysis occurs when macerated blood or thrombus is not removed by the catheter. Transient mechanical hemolysis of 24-48 hours duration was reported following catheter thrombectomy, particularly with the Amplatz device and with hydrodynamic devices such as the Angiojet catheter (23).